Thromboembolic Disease

Question 1

Red thrombus

Answer 1

Fibrin-rich with a lot of red blood cells, occurs in veins

Question 2

White thrombus

Answer 2

Platelet rich, in arteries

Question 3

Prothrombotic factors that lead to thrombosis

Answer 3

Endothelial injury, abnormal blood flow, hypercoagulability or hypofibrinolysis

Question 4

Drug classes for thromboembolic diseases

Answer 4

Systemic anticoagulants, antithrombotic drugs, fibrinolytic drugs

Question 5

Systemic anticoagulants

Answer 5

Heparin, warfarin, rivaroxaban, bivalirubin, dabigatran

Question 6

Reperfusion injury

Answer 6

Bad remnants from occlusion can shower tissue and cause injury

Question 7

Heparin mechanism

Answer 7

Accelerates action of antithrombin III (ATIII)

Question 8

Antithrombin III

Answer 8

Inhibits activated clotting factors through thrombin and (Xa they will remain bound and inactive)

Question 9

Properties of heparin

Answer 9

Highly negatively charged, from mast cells

Question 10

Uses for heparin

Answer 10

Initial treatment of thrombosis and thromboembolic diseases

Question 11

Onset of heparin

Answer 11

Rapid, useful as an acute anticoagulant

Question 12

What heparin does not do

Answer 12

Fibrinolysis

Question 13

Adverse effects of heparin

Answer 13

Bleeding tendencies, thrombocytopenia, monitor with aPTT o use protamine sulfate in overdoses

Question 14

Enoxaparin

Answer 14

Low MW heparin; inactivates Xa but not thrombin

Question 15

Benefits of enoxaparin over unfractioned heparin

Answer 15

Less bleeding tendencies, less risk of thrombocytopenia, longer half-life so you can give subcutaneously

Question 16

Warfarin

Answer 16

Oral anticoagulant

Question 17

Warfarin mechanism

Answer 17

Prevents vitamin K from being reduced so clotting factors are not activated, not effective until existing coagulation factors are used

Question 18

Warfarin monitoring

Answer 18

International normalized ratio (INR)

Question 19

Toxicities of warfarin

Answer 19

Bleeding tendencies, crosses placenta (heparin does not)

Question 20

Rivaroxaban

Answer 20

Directly inactivates factor Xa, nothing else

Question 21

Uses for rivaroxaban

Answer 21

Prevention of stroke from atrial fibrillation, prevent of deep venous thrombosis and pulmonary embolism

Question 22

Bivalirudin

Answer 22

Inhibits only thrombin, from leeches and given intravenously, binds both active site and exosite

Question 23

Dabigatran

Answer 23

Oral thrombin inhibitor that only binds the active site

Question 24

Therapeutic targets of antithrombotic drugs

Answer 24

Collagen, thrombin, ADP, 5HT, TXA2, COX, cAMP, cGMP, Ca2+

Question 25

Antithrombotic drugs

Answer 25

Aspirin, clopidogrel, prasugrel, ticagrelor, abciximab, eptifibatide

Question 26

Aspirin

Answer 26

Most commonly used anti-platelet drug, irreversibly binds COX1

Question 27

What aspirin prevents

Answer 27

Thrombus formation

Question 28

What aspirin does not do

Answer 28

Lose existing thrombi

Question 29

Adverse effects of aspirin

Answer 29

Ulcers, renal damage, bleeding

Question 30

Clopidogrel, prasugnel, ticagrelor

Answer 30

P2Y12 receptor antagonists so ADP cannot bind other platelets; some have to be activated by P450 enzymes, all are orally available and fairly safe

Question 31

Glycoprotein IIb/IIIa

Answer 31

Receptor on surface of platelets for fibrinogen, anchors platelets together

Question 32

Abciximab

Answer 32

Fab fragment of monoclonal antibody against IIb/IIIa receptor; irreversibly inhibits the receptor so platelets can’t aggregate

Question 33

Toxicity of abciximab

Answer 33

Bleeding tendencies

Question 34

Eptifibatide

Answer 34

Peptide that reversible inhibits the IIb/IIIa receptor, with similar adverse events as abciximab

Question 35

Fibrinolytic drugs

Answer 35

Alteplase, tenecteplase

Question 36

Alteplase

Answer 36

TPA, activates plasmin, short half-life

Question 37

Toxicity of alteplase

Answer 37

Bleeding tendencies

Question 38

Tenecteplase

Answer 38

Variant of TPA with less bleeding tendencies and longer half-life